Objective
Heart failure is currently the most serious complication of
muscular dystrophy. The
transient receptor potential cation channel, subfamily V, member 2 (TRPV2) is a stretch-sensitive Ca channel. In damaged myocytes or cardiomyocytes, TRPV2 translocates to the cytoplasmic membrane and enhances Ca influx, triggering cell damage. Evidence suggests that the inhibition of TRPV2 may be a new therapeutic target in
heart failure. We found that
tranilast, which is widely used as an
anti-allergic drug, inhibits TRPV2. A pilot study was conducted to assess the safety and efficacy of
tranilast in
muscular dystrophy patients with
cardiomyopathy. Methods After obtaining informed consent, two
muscular dystrophy patients with advanced
heart failure took
tranilast (300 mg/day) for three months. Blood tests, echocardiography, electrocardiography (ECG), Holter ECG, analyses of the TRPV2 expression in peripheral mononuclear cells, and circulating micro
ribonucleic acid profiling were performed to assess the safety and efficacy of
tranilast. Results The
brain natriuretic peptide levels decreased
after treatment. The expression of TRPV2 on the cytoplasmic membrane of peripheral mononuclear cells was enhanced before treatment and was decreased
after treatment. Some heart-related micro
ribonucleic acids (miR-208a-5p, miR-223-3p) were elevated and then decreased
after treatment. Some adverse events, including the potentiation of
warfarin, the worsening of renal dysfunction, an increased heart rate and
premature ventricular contractions, were observed. Conclusion
Tranilast can inhibit TRPV2 and can be effective for treating
heart failure, even in patients with
muscular dystrophy. Although careful attention is needed, the inhibition of TRPV2 can be a new treatment target for
cardiomyopathy. A multi-center trial is planned.